The announcement last week by the U.S. Fish and Wildlife Service that 23 more species are now officially declared extinct was a sobering reminder of our collective human impacts on this diverse group of organisms. The list includes 11 birds, eight freshwater mussels, two fish, a bat and a plant. Many of these were probably extinct, or close to it, when the Endangered Species Act was passed in 1973.
On the positive side, since the passage of the act 48 years ago, 54 species in the United States have been removed from the endangered list because their populations have recovered, while another 48 have improved enough to be moved from endangered to threatened; not completely out of the woods, but good signs. Closer to home here on the central coast, The Marine Mammal Protection Act of 1972 and the elimination of DDT were both important steps in bringing back the southern sea otter, the brown pelican and the peregrine falcon from the brink of extinction.
The southern sea otter was hunted for its fur by the Russians from the late 1700s to the mid-1800s when they were thought to have become extinct. In 1938, however, when the Big Sur Highway was completed, a group of about 90 otters was seen on the Big Sur coast near Bixby Creek. Thanks to protection, this group has in the subsequent years slowly grown to a population of about 3,000 at present.
The peregrine falcon population is another success story, due in large part to the dedicated and sustained efforts of the Santa Cruz Predatory Bird Research Group based at UC Santa Cruz. The high concentrations of DDT in these birds led to very thin eggshells and the loss of the chicks. With the elimination of DDT these unique and amazing raptors have rebounded to a population today of about 300 breeding pairs in California.
The brown pelicans underwent a similar response to the effects of DDT, with very few eggs successfully hatched due to thin shells for a number of years. From a combination of the 1972 banning of the use of DDT, as well as efforts by states, conservation organizations, private citizens and many others, then Secretary of Interior, Ken Salazar, and two other federal officials announced in November 2009 that the Brown Pelican had recovered and was being removed from the list of threatened and endangered species.
At that time there were more than 650,000 of these iconic birds found across Florida and the Gulf and Pacific Coasts as well as in the Caribbean and Latin America.
The banning of the pesticide DDT (more completely known as dichloro-diphenyl-trichloroethane) was due to the dedication, persistence and uphill battle of biologist Rachel Carson and the publication of her book, Silent Spring. For her efforts, she was called a communist and a hysterical woman. In a September 28,1962 book review, Time magazine accused Carson of publishing “downright errors” and “scary generalizations.”
Chemical-industry trade groups, agricultural journals and other opponents of pesticide restrictions published attacks on Silent Spring. One pesticide manufacturer threatened legal action in an attempt to prevent publication of the book. Instead of being suppressed, however, Silent Spring rocketed to number one on the New York Times best-seller list.
Sadly, Rachel Carson died of breast cancer in 1964, two years after presenting modern environmentalists with a bible. Her legacy was eventually the nation-wide ban on DDT in 1972, and the creation of the Environmental Protection Agency in 1970, which may likely have not been established without Rachel Carson’s efforts. UCSC, honored her with the naming of College 8 as Rachel Carson College in 2016, thanks to the help of an endowment from the Helen and Will Webster Foundation.
Gary Griggs is a Distinguished Professor of Earth and Planetary Sciences at UC Santa Cruz. He can be reached at griggs@ucsc.edu. For past Ocean Backyard columns, visit http://seymourcenter.ucsc.edu/about-us/news/our-ocean-backyard-archive/.
